I agree with Melanie32. Just reading great living books is definitely enough for a 1st grader.
In fact, in my experience with my boys, discussing the book and giving commentary tends to turn them away from the book. My boys like to read books and think about them on their own terms. It’s surprising that a book will come up in conversation weeks later.
A great example – we were reading about the explorer James Cook. We traced his route on the map, read the story about his adventures, and other than a quick narration we didn’t discuss it at all. Later that week, though, I found my 9YO looking up information about the Great Barrier Reef. He was thinking about James Cook’s ship being damaged by the reef and decided he wanted to see pictures for himself. He was thinking about the story all week and I didn’t even realize it!